Global trends in the increasing prevalence of the fosfomycin resistance gene in Staphylococcus aureus
Authors: Daniel F M Monte, Celso Jose Bruno de Oliveira
Journal: The Lancet Microbe (2023)

The FosB enzyme confers resistance to fosfomycin, an antibiotic used to treat various bacterial infections. In Staphylococcus aureus, the fosB gene can be either plasmidial or chromosomal, which exemplifies the adaptability and persistence of antibiotic resistance mechanisms in bacterial populations.1Fu Z Liu Y Chen C et al.Characterization of fosfomycin resistance gene, fosB, in methicillin-resistant Staphylococcus aureus isolates.PLoS One. 2016; 11e0154829Google Scholar The fosB gene can spread among S aureus strains and other bacteria through plasmids and confer fosfomycin resistance, which is a concern in clinical settings. The presence and distribution of antibiotic resistance genes in S aureus, such as fosB, are of paramount concern in the field of microbiology and public health.2Hu J Chen L Li G et al.Prevalence and genetic characteristics of fosB-positive Staphylococcus aureus in duck farms in Guangdong, China in 2020.J Antimicrob Chemother. 2023; 78: 802-809Crossref PubMed Scopus (2) Google Scholar Therefore, we analysed 106 005 genomes to uncover the global distribution of fosB genes in clinical and non-clinical S aureus strains. Our results revealed that 59 065 (55·7%) of 106 005 S aureus strains harboured the fosB gene. Our comprehensive genomic analysis of the global distribution of S aureus strains carrying fosfomycin resistance genes revealed their presence in 34 countries (appendix). This prevalence extends to several continents, highlighting the widespread nature of this resistance mechanism. The global distribution of fosB genes underscores the need for international collaborations and surveillance to track and mitigate the spread of antibiotic resistance effectively. Fosfomycin is a valuable antibiotic for treating meticillin-resistant S aureus (MRSA) infections, particularly when other antibiotics might be less effective owing to resistance.1Fu Z Liu Y Chen C et al.Characterization of fosfomycin resistance gene, fosB, in methicillin-resistant Staphylococcus aureus isolates.PLoS One. 2016; 11e0154829Google Scholar However, fosB is a crucial genetic element found in epidemiologically relevant MRSA strains associated with both hospital-acquired1Fu Z Liu Y Chen C et al.Characterization of fosfomycin resistance gene, fosB, in methicillin-resistant Staphylococcus aureus isolates.PLoS One. 2016; 11e0154829Google Scholar and community-acquired staphylococcal infections.3McManus BA Aloba BK Earls MR et al.Multiple distinct outbreaks of Panton-Valentine leucocidin-positive community-associated meticillin-resistant Staphylococcus aureus in Ireland investigated by whole-genome sequencing.J Hosp Infect. 2021; 108: 72-80Summary Full Text Full Text PDF PubMed Scopus (10) Google Scholar The presence of fosB in MRSA strains represents one facet of the complex genetic arsenal that these bacteria have evolved to combat antibiotics. MRSA is also known for its resistance to multiple classes of antibiotics, including beta-lactams such as meticillin. The acquisition and expression of genes such as fosB contribute to the multidrug-resistant phenotype shown by MRSA. Indeed, we uncovered compelling evidence supporting the co-occurrence of MRSA strains carrying the fosB gene with S aureus strains. 36 222 (61·3%) of the 59 065 fosB-harbouring S aureus strains carried the meticillin resistance determinant mecA and 20 (0·03%) strains carried the mecC homologue. 37 918 (64·1%) genomes also harboured the beta-lactamase blaZ gene. In conclusion, the global distribution of fosB genes in S aureus represents a key issue in the ongoing battle against antibiotic resistance. Understanding the genetic, molecular, and epidemiological aspects of this resistance mechanism is essential for developing strategies to preserve the effectiveness of antibiotics in the face of evolving bacterial threats. Attaining such an understanding should further underscore the importance of multidisciplinary research, surveillance, and international cooperation in addressing the complex and dynamic nature of antibiotic resistance in clinical and environmental settings. We declare no competing interests. This research was funded by Coordination for the Improvement of Higher Education Personnel (CAPES) (Finance Code 001). CJBO holds a Research Productivity Fellowship (Level 1-D) granted by the Brazilian National Council for Scientific and Technological Development (CNPq, proc. 3136678/2020-0). DFMM holds a postdoctoral research fellowship granted by Fundação de Apoio à Pesquisa do Estado da Paraíba (Fapesq 88887.898770/2023-00). Download .jpg (2.21 MB) Help with files Supplementary appendix